370 SPECIFIC MICRO-ORGANISMS 



upon this deduction have been remarkably successful in the sup- 

 pression of the disease. 



Seidelin 1 has described a minute structure which occurs in the 

 blood cells and in the blood plasma in yellow fever, which he has 

 called Paraplasma flamgenum and regards as the pathogenic 

 agent. The work lacks confirmation by other observers and the 

 evidence is not yet convincing. The earlier papers of Seidelin have 

 been severely criticised by Agramonte. 1 



The Virus of Cattle Plague (Rinderpest). This organism 

 occurs in the blood, organs and excretions of cattle suffering from 

 the disease. It was shown to be filterable by Nicolle and Adil- 

 Bey in 1902, and is able to pass through the Chamberland "F" 

 filter. The virus resists drying for four days and remains active 

 for two or three months when spread on hay in a dark place. 

 It is destroyed by distilled water in five days, by glycerin in eight 

 days and rendered avirulent in a few hours by admixture of bile. 

 The disease is an acute febrile disorder characterized by severe 

 inflammation of the mucous membranes and rapid emaciation. 

 It is usually fatal. Immunity follows recovery and is induced 

 artificially by injecting the bile of infected animals under the 

 skin of the healthy cattle. In this way an active immunity is 

 acquired without an evident attack of the disease. 



The Virus of Rabies. This organism exists in the central 

 nervous system, the peripheral nerves, the salivary glands, the 

 saliva and less frequently in other parts of the body of persons 

 or animals suffering from lyssa or rabies. The virus was filtered 

 by Remlinger in 1903. It may also be dialyzed through collodion 

 sacs. 3 The virus is rendered inert by drying for two weeks, and 

 by heating at 55 C. for 30 minutes, by admixture of bile in a few 

 minutes, and by the gastric juice in 5 hours. It remains virulent 

 in glycerine for several months. Negri in 1903 described certain 

 bodies which seem to occur in the central nervous system in- 

 variably and exclusively in this disease. They are especially 



1 Bull. Yellow Fever Bureau, 1912, Vol. II, pp. 123-242. 



1 Medical Record, 1912, Vol. LXXXI, pp. 604-607. 



2 Poor and Steinhardt, Journ. Infect. Dis., 1913, Vol. XII, pp. 202-205. 



